Generally described, network-based services can maintain information about various customers and/or services provided to customers. As the number of customers and the available services over the networks increase, the amount of customer information maintained in database systems for network-based services can also greatly increase. In some situations, however, the conventional database system resources, such as storage capacity and processing capacity, cannot keep up with the increasing volume of customer information.
One solution may be adding additional database resources, such as computer hardware, as the demand for a higher database capacity arises. However, adding new computer hardware can be expensive and logistically difficult. For example, the addition of additional computer hardware to a database system can require redistribution or migration of data from the existing database hardware to the new database hardware and often deployment of a new software system. Moreover, at some point in the process of the redistribution or migration of data, the existing database and the new database may often be locked from access in order to ensure data consistency. This may disturb various network-based services that require immediate access to information stored in the existing database hardware.